Just about every country except those in North America use hectopascals for airport pressure, primarily because it required no modification of aircraft altimeters which previously used millibars. In Canada and the United States airport pressure is reported in Inches of Mercury (inHg). Many Central American countries will give the pressure in inches of Mercury to American aircraft, but the original reading is in hectopascals.
In the upper atmosphere, winds are normally displayed on different pressure levels like the 500 hPa or 200 hPa altitude. This also applies in the US where it's still labeled as mb. 18000 ft is 500 mb, 36000 ft is 225 mb, etc. http://aviationweather.gov/adds/winds/ Mike Payne On 24/08/2011, at 22:14 , John Candido wrote: > Hi, I live in Australia and we are predominantly a metric nation. However, > we have not been consistent with things such as the measurement of blood > pressure in medicine and air pressure in meteorology. The measurement of > blood pressure in millimetres of mercury instead of kPa (kilopascals) is a > prime example of this inconsistency. A normal blood pressure reading for an > adult in millimetres of mercury is 120 on 80, and its equivalent in kPa is 16 > on 10. In addition, what about the measurement of air pressure in millibars, > which is the current method? Will this be converted to hectopascals of air > pressure in the future? Thank you. > > Sincerely yours, John Candido. >
